NOMENCLATURE, PHOTOORAPHIC.—The nomenclature of the various photographic inventions and processes seems to have been carried out without the slightest regard to law or order. The most absurd and meaningless words have been adopted, and which are in many cases liable to lead the student astray.
At an International Photographic Congress held in Paris in 1890 the following rules were laid down as a basis for a system of rational nomenclature : r. The expression photo shall be employed to the exclusion of the word hello to indicate processes due to the action of light from any source whatever, and not alone to the action of solar light. The expression helix is exclusively reserved to indicate those processes only in which solar light is used.
2. The expressions positives and negatives are reversed to indicate respectively the images in which the effects of light and shade resemble those of nature, or in which those effects are reversed.
3. In that which concerns photographs obtained solely by the chemical action of light, the name of phototypes will distinguish those produced directly by the use of the camera. The name will be given to the reproductions of these by a new photographic operation by means of a sensitive surface acted upon by light.
The name (photo-sketches ?) will be given to reproductions made in the same way from non-photographic original designs.
4. Photo-mechanical prints, or phototirages, which may also be called photo prints, will be differentiated by the following appellations : To designate these different processes, an insertion will be made between the two radicals which form the word and which will indicate the principal characteristic of the par ticular process.
According to this rule the word will indicate reproductions in various inks by processes in which colloids (gelatine, albumen, bitumen and so on) are spread upon various supports, and rendered fit for inking by the action of light.
The word photo plastography will be employed to indicate processes in which a plastic substance changes its form because of the action of light, and returns to a thickness suitable for a colored gelatinous ink.
The word will be used for processes of engraving in intaglio by photography.
The word will be employed for photographic processes of engraving in relief for use in the type - high letter printing press.
The word will be applied to printing processes for the reproduction of photographic images of several colors.
5. More extended designations of photographic processes or operations may be applied, so far as the French language is concerned, by introducing generic words preceding the necessary indications of the nature of the processes or operations.
For instance, the preposition or a par (by). according to the case, will precede the words indicating sensitized substance employed, or that of the mode of operation ; and the preposition upon precede the words indicating the nature of the support of the preparations. The names of the inventors, if they have to be used, can be placed at the end.
Positive photo-type ; iodide of silver on a metallic plate (Daguerre's process). 2. Positive photo-type ; collodion on a metallic plate (Ad. Martin's pro cess). 3. Negative photo-type ; collodidio-bromide of silver on glass. 4. Positive photo-copy ; gelatino-chloride of silver on paper. 5. Positive photo-copy, in mixed colors (Poitevin's process).
6. Negative photo-sketch ; ferro prussiate blue paper (Motileff's process). 7. Positive photo sketch ; gallate of iron. Photo-collography ; bichromated gelatine on ground glass 9. ; colored gelatinous inks (Woodbury's process). 10. Photo-glyptog Newt, Feb. 21, ago.
raphy, by bitumen of Judea on steel (Ni6pce's process). r i. Photo-typography, by bitumen of Judea on zinc.
6. For the designation of the divers applications of photography to especial purposes, are reserved several compound words, obtained by prefacing the photography with radicals indicat ing by abbreviation the particular applications